Separable rock drill



Dec. 10, 1929. o. GARINO 1,738,883

SEPARABLE ROCK DRILL Filed June 27, 1929 inventor 012 x2 0 fara'iw M A iiorney atented Dec. 10, 1929 UNITED STATES onnsrn ammo, or" BUTTE, MONTANA.

SEPARABLE ROCK DRILL Application filed June 27, 1929. Serial No. 874,136.

This invention relates to a separable rock drill and an object of the invention is to provide a drilkhaving a point separable from the shank so that the points may be changed with dispatch when they become dulled or in need of dressing and repair.

Another object of the invention is to provide an interchangeable point on a rock drill that cannot get out of alinement with the w shank regardless of the position of the shank.

Another feature of the invention is the provision of a drill bit that requires no machinery and is capable of being forged into its shape thereby promoting economy of production.

Another feature of the invention is to provide a drill point which will at all times direct waterto the drill bit without danger of becoming clogged or otherwise obstructed with the cuttings of the drill hole. I

A further feature of the drill is a slot in the shank which permits of sufficient spring therein to allow the bit to be inserted with slight force, and at the same time to securely hold the point in position.

Other objects of the invention are to provide, in the manner as hereinafter set forth, a drill of the character referred to, which is strong, compact and durable. thoroughly efiicient for its intended purpose, permitting replacement with easeand dispatch, very simple in its method of assembly, and comparatlvely inexpensive to manufacture and install.

With the foregoing and other objects in view, the invention consists of a novel construction, combination and arrangement of parts, to be hereinafter more specifically described and illustrated in the accompanying drawings, which discloses an embodiment of the invention, but'it is to be understood that changes, variations and modifications may be resorted to without departing from the spirit of the claims hereto appended.

In the drawings, wherein like reference characters denote corresponding parts, throughout the several views:

Figure 1 is a side elevation, partly broken away and in section of the drill assembled 5G in, accordance with the present invention,

Figure 2 is a fragmentary side elevation of the lower end of the shank drill,

Figure 3 is a top plan view of the bit, and,

Figure 4 is an end View of the shank of the drill in which is seated the bit.

Referring to the drawings in detail, 5 indicates generally the shank of the drill in accordance with the present invention and 6 indicates generally the separable bit adapted for detachably seating, in a manner to be presently described, in the shank 5. The shank 5 is of square-cross section at its upper end, and for a major portion of its length so as to be adaptable for fitting in the sockets of the conventional air or steam impact hammers.

Concentric with respect to the axis of the shank 5, the lower end thereof is formed with a substantially circular socket 7 which is curved slightly in a longitudinal direction and merging at its inner end with a diametrically disposed groove 8 which is substantially U-shaped in cross section. The length of the groove 8 is equivalent to the diameter of the socket 7 and at its inner end" merges with a circular opening 9 which extends from the upper end of the shank along the axis thereof.

The opening9 conducts water or other lubricatin means through the shank to the lower end tfiereof. The opening 9 is concentric with the socket 7 but of materially less diameter than said socket, and both are concentric with respect to the axis of the shank. The lower end of the shank 5 from the outer end of the socket 7 is curved as indicated at 10 and is slightly larger than the width of the shank. A segmental shaped slot'll described from a point eccentric with respect to the axis of the shank is formed on the lower end thereof,

as will be clearly understood by referring whereby the bit may be pried loose in t1.

event of sticking or otherwise lodging in the shank.

The drill bit 6 has a central body portion 13 from which radiates at quadrants therefrom, legs 14 having inset channels 15 therebetween. The lower face of the body portion 13 and the legs are formed with conventional star cutting edges 16.

The upper end of the body portion 13 merges with an upstanding shank 17 which has a snug fit in the socket 7 and at the upper end of the shank 17 is formed an upwardly projecting boss 18 which fits in the transverse groove 8 to prevent the drill bit from turning, when the bit is detachably seated in the socket 7. The shank 5 should be formed of steel having suflicient elasticity to spring the walls of the socket when shank 17 is inserted therein. At a point where the body portion 13 merges with the shank there is formed a circular concavity 19 that receives the rounded lower end 10 of the shank so as to form a rigid seat therefor free of lateral movement regardless of its position.

The diameter taken through the laterally projecting legs 14 is materially greater than I the width. of the shank 5 so as to provide proper clearance for the drill bit 6. The water flowing through the shank 5 from the upper end thereof passes through the passage 9 into the slot 11 whereby the said water is dispersed to the opposite sides of the shank and downwardly through the channels 15 to the cutting point 16.

It is to be noted that there are two-fold precautions taken, to prevent any lateral movement of the bit 6 with respect to the shank 5 by reason of providing the concavity 19 adjacent the shank 17 on the bit for seating the curved lower edges 10 of the shank and the foregoing being in addition to the round socket 7 and the transverse groove 8.

His to be understood that by describing the invention by detail herein, any particular form, structure or arrangement, is not intended to limit the invention beyond the terms of the several claims or the requirements of the prior art.

, Having thus described my invention, what I claim as new is:

1. A rock drill comprising a shank portion and a bit portion removably seated in said shank portion, said shank portion having a socket at its lower end merging at its inner end in a diametrically disposed groove, said shank portion further having an opening extending from its upper end and terminating in said groove, said shank portion further provided with a slot communicating with said opening and terminating at the lower end of the said shank portion on'opposite sides of the socket, said bit portion formed of a body portion having laterally projecting legs provided with channels between said legs in communication at their upper ends with said slots and having cutting edges on the lower ends of the legs and the body portion, said body portion merging at its upper end with a shank for detachably seating in the socket and said shank merging with a raised boss for seating in said groove to prevent turning of the bit portion with respect to the shank portion of the drill.

2. A rock drill comprising a shank portion andabitportionremovablyseatedinsaid shank portion, said shank portion having an ovalshaped socket at its lower end merging at its inner end in a diametrically disposed groove, said shank portion further having an opening extending from its upper end and terminating in said groove, said shank portion further provided with a slot communicating with said opening and terminating at the lower end of the said shank portion on opposite sides of the socket, said bit portion formed of a body portion having laterally projecting legs provided with channels between said legs in communication at their upper ends with said slot and having cutting edges on the lower ends of the legs and the body portion, said body portion merging at its upper end with a shank for detachably seating in the socket and said shank merging with a raised boss for seating in said groove to prevent turning of the bit portion with respect to the shank portion of the drill, the lower end of the shank portion curved between the socket and its periphery, and the body portion of the bit portion having an annular concavity to seat the curved end of the shank portion to provide additional resistance to lateral movement of the bit with respect to the shank.

3. A. rock drill comprising a shank portion and a bit portion removably seated in said shank portion, said shank portion having a substantially circular socket provided at its lower end with curved walls longitudinally thereof and merging at its inner end in a diametrically disposed groove, said shank portion further having an opening extending from its upper end and terminating in said groove, said shank portion further provided with a slot communicating with said opening and terminating at the lower end of the said shank portion on opposite sides of the socket, said bit portion formed of a body portion having laterally projecting legs provided with channels between said legs in communication at the upper ends with said slot and having cutting edges on the lower ends of the legs and the body portion, said body portion merging at its upper end with a shank for detachably seating in the socket and said shank merging with a raised boss for seating in said groove to prevent turning of the bit portion with respect to the shank portion of the drill, the lower end of the shank portion curved between the socket and its periphery and the body portion of the bit portion having an annular concavity to seat the curved meeeee end of the shank portion to proviote etditiona1 resistance to lateral movement of the bit with respect to the shank, a, ortion of the inner Wall of said slot located a ove the trans verse groove to provide for prying the bit shank from the socket in case of sticking.

In testimony whereof I afix my signature ORESTE GINO. 

